Two Japanese ministers have visited a controversial Tokyo war shrine, in a move that could further strain relations between neighbouring China and Korea.

Transport minister Yuichiro Hata of the ruling Democratic Party (DPJ) and postal reform minister Mikio Shimoji of People's New Party were part of a group of lawmakers seen at Yasukuni Shrine to commemorate Japan's autumn festival.

The Shinto shrine in central Tokyo honours 2.5 million war dead, including 14 convicted Class A war criminals from World War II.

Visits to the shrine by government ministers and high-profile figures spark outrage in China and on the Korean peninsula, where many feel Japan has failed to atone for its brutal aggression in the first half of the 20th Century.

Hata has told local media his visit was "private "and would not cause any trouble."I visited as a secretary general of the People's New Party," he said.

"It won't be a big diplomatic problem.

Japan's Opposition leader Shinzo Abe visited the shrine on Wednesday, prompting criticism from Chinese state media."At such a delicate moment, Abe's visit... has added insult to injury and dealt another blow to the already fragile Sino-Japanese relations," the Xinhua news agency said.

Ties between Japan and China have been strained recently due to their competing claims for a group of islands in the East China Sea.

Japan's prime minister, Yoshihiko Noda, has been careful to stay away from the shrine and previously told his cabinet to do the same.